The Fourth International Research Workshop on Alopecia Areata will bring together investigators working in this field. The purpose of this conference is to review the current state of knowledge and foster international collaborations for further research on this disease. The hypothesis is that alopecia areata (AA) is a genetically determined, organ specific, autoimmune disease directed against the hair follicle and mediated by T cells. Speakers working in the field have, therefore, been selected to review the areas of autoimmunity, genetics, targets and controls, and treatment. The keynote speaker will focus on fundamental research dealing with hair follicle biology. Funding is requested to help defray the costs for invited speakers and trainee awards to enable young investigators or trainees to present their work at this meeting. This research conference will focus on the latest developments in the pathogenesis of AA. First, arguments for and against AA being an autoimmune disease will be debated including and overview of immunology of the skin and hair follicles. Next, progress in gene array and mapping studies using human patients and rodent models will be presented. Focus on the status of the National Alopecia Areata Registry and access to it will be given. Human patient and animal model studies will provide the background for updates on targets, triggers, and controls for hair follicles in general and AA in particular. Integration of the latest research findings with new AA therapies on the horizon will sum up the formal presentations. The evening session will be a poster discussion session in which new work will be presented.